Are Tankless Water Heaters the Best? – DSP 270

Graham and Jake take on talking about Tankless or “On Demand” water heaters today. They break down a lot of the benefits of them compared to storage water heaters like the fact that they provide a nearly limitless source of hot water, require less energy consumption, etc. They’re not perfect though, and any float center considering one should look closely on how best to implement them. Jake shares some of the pitfalls of them as well as how to maximize their usefulness.

EnergyStar’s Water Heater Rating System

Further Reading on UEF Rating

More Info on Re-circulation Pumps

Listen to Just the Audio

Transcription of this episode… (in case you prefer reading)

Graham: All right. Hello, everybody. This is a Graham over here.

Jake: And I’m Jake.

Graham: And boy, do we have a question for us from are you?

Jake: Oh boy.

Graham: And the question is “I’ve been looking into water heaters. It seems like tankless water heaters are the way to go. Is there any reason I should choose something else?”

Jake: Oh. Well, with-

Graham: You look a little worried over there.

Jake: Well the budget is the main concern. You could always just have cold showers, right. Like there’s that option.

Graham: No water heater.

Jake: Yeah, no water heater. Like if we’re talking about what are your options. No, but you should probably heat the water that your clients are going to use.

Graham: It does make your tank water seem really nice and toasty after wards is the benefit of cold showers.

Jake: Oh, yeah. Right? Like they’re married reasons, yeah. All right, all right. So, basically the question is tankless water heaters, on demand water heaters versus storage tank versus-

Graham: Anything. yeah. Storage tank, I guess yeah. Like so tankless as opposed to something with-

Jake: Right. So I guess the storage tank water heater one of the most common, and I guess also there’s boiler systems and stuff. There’s solar. I guess I shouldn’t just say they’re only those two.

Graham: I feel like I always maybe get this wrong or maybe get it right. Is tankless water heaters the same as on demand?

Jake: It is.

Graham: Water heaters that just-

Jake: Exactly.

Graham: Okay, great. Then I haven’t been lying.

Jake: No. That’s good.

Graham: Yeah. Good. Good.

Jake: No, same thing. Tankless/on demand. The idea there is that there’s no storage tank. They might even be referred to as on demand more often. The idea is that-

Graham: Just some more points for Graham.

Jake: Yeah. No, it’s just the water is, you have hot water on demand. You’re not storing anything. You’re not continuously heating it. You’re only using energy when you’re actually using the hot water. So there’s some efficiency things going there.

Graham: And that’s opposed to having a this big body of water-

Jake: A storage tank unit. Yeah.

Graham: Where it’s just and that’s where you’re heating it. You’re like-

Jake: Oh, yeah.

Graham: You’re storing it in there. And you’re heating up the water in the storage tank and-

Jake: Constantly suffering from latent heat loss, is what that is.

Graham: And that by far as the most common?

Jake: Yes. storage tank water heaters-

Graham: Residentially and commercially.

Jake: Yeah, absolutely.

Graham: Like, you see them everywhere. You have one in the bottom of your house-

Jake: Very common.

Graham: Right now most likely.

Jake: Yeah. Price point. Much lower price point compared to tankless units and stuff like that. Okay, let’s talk about a couple of them. Like how they’re rated and like, what you’re doing with them and what you need it for at your center.

Graham: Yeah.

Jake: First and foremost, kind of like electricity, you’re doing a load calculation for that, you’re going to be doing a load calculation for the amount of water that you want to be using in your space. Keeping in mind that you have people showering at a couple gallons per minute and they all shower and then a new group of people, however many tanks you have, comes in right after them and showers again. We’re running two showers for every float like that shower business almost, you know what I mean?

So we need to provide hot water. You can look at storage tank water heaters. They’re going to take up a footprint within your shop somewhere. They are rated on their first hour rating, basically. How much hot water can we give you in one hour if this tank is already filled with hot water? And the tankless water heaters, the way that they’re rated is how much can I change the temperature of the source water at a given flow rate to give you your desired temperature of 110, 120, whatever your building code is for that area.

As long as we’re talking about ratings, it is worth noting that last year, in June 2017, the Department of Energy, they actually devised a new system of rating different water heaters. I want to make it a little bit easier to compare things, apples to apples, make sure it’s easier to look at these two things when you’re comparing them next to each other. It’s UEF, Uniform Energy Factor, I believe is what that actually stands for.

It’s a little different than the old EF system that they’re using, basically just telling you the efficiency of the unit. How much of the energy are you putting into that unit that actually converts into warm water, something that we’re actually using or something like that. This new system breaks up different units into four tiers, four bins is what they call them. And then within that tier of water heater, they rate those. And the higher the UEF, the more efficient it is, which means the more money you’re going to save to be completely honest and the less energy you’re going to waste for the environment and everything like that.

Graham: So is that new rating for tanked water heaters or is it for both?

Jake: It is for both.

Graham: Okay, interesting.

Jake: They’re making this universal Of course. Like it’s within bins. You know what I mean, they’re compartmentalizing these things. But it’s all across the board. It is only for residential units right now, not commercial units. But a lot of floating centers, they’re purchasing residential units. They’re using those within their space because they tend to be a little bit cheaper. And again, we’re only using it for showers. We don’t need hotter than 120 degree water basically.

So this is currently only for residential units. But it is worth noting, again they broke it up into four tiers. And within those tiers the higher the rating, the more efficient it’s going to be. Also another thing to note is that if two water heaters are in different tiers from each other, then those ratings do not directly compare. So you’ll have something in the high tier saying it has a 0.95 rating and then something in the low tier that has a 0.95 reading. When you look at that and you only see the 0.95, just realize that’s not the whole picture. You should definitely check out what tier you’re in because those are not directly relatable.

Graham: And fortunately, it’s become really standard practice as well to have stickers on the-

Jake: Absolutely.

Graham: Appliances that actually say exactly how much it would cost at normal water usage. .

Jake: Yeah.

Graham: And so even if all of this the kind of rating systems themselves sound intimidating or it sounds like there’s a lot to learn there. Again, the nice thing is that I think that there’s this push to making it more understandable to consumers.

Jake: For sure.

Graham: Right down to, “Hey, here’s a dollar amount that you can expect-

Jake: Absolutely.

Graham: From here and then you can compare those dollar amounts against each other.” So there’s like when I was looking into it there’s probably almost three to four, five different ways to look at what you’re comparing from water heaters, it’s absolutely crazy.

Jake: Oh, yeah, absolutely. That’s why they trying to make it a uniform.

Graham: Yeah. That will make sense.

Jake: I mean, like that’s the idea is, like before-

Graham: And so just to kind of piggyback on this too.

Jake: Okay.

Graham: This is also one of those areas where although tankless water heaters are more expensive, they are more efficient theoretically. Normal you have this body of water that you’re heating and all that heat escapes through the side of the tank. It’s in the pipes and is escaping through there. So you’re kind of heating a lot of water or a lot of the heat that you’re that you’re putting into the water is not being used when it reaches the shower. It’s kind of just dispersing.

Jake: Which creates one interesting thing.

Graham: Oh, and just real quick. But for tankless water heaters, because you’re only heating it when it’s passing through, you’re not wasting any of that heating energy.

Jake: Right. So, that’s what leads to this interesting thing about tankless or on Demand water heaters, is if it’s only heating when water is actually passing through it, you can end up in a situation, it’s pretty common, it’s called the cold water sandwich effect. It’s a phenomenon where you basically have

Graham: My least favorite kind of sandwich.

Jake: So basically, you still have warm water in the lines coming up to your shower, or maybe in the faucets like right in the taps there. But then you turn on your shower, and then all of a sudden, you start pulling through cold water into the system. And now that cold water is running through your lines towards you. And it takes a little bit for the heat exchanger inside those tankless water heaters to heat up. An electric one, it takes quite a bit longer than a gas unit because gas, the heat recovery rate is just so much quicker for gas. So it can heat up pretty quick. So it’s a small, thin sandwich.

Whereas like if you only have one tankless water heater per room and your floats are spread out. And you can end up in a situation where you could have a warm blast, a cold blast that you have to sit and stand through and then it’s up to the temperature that you really want. And what we’ve heard of some people doing to kind of get around that cold water sandwich effect, is they’ve incorporated recirculation pump. We have storage tank water heaters at Float On. And we use a recirculation pump. Basically, we’re cycling the water through the lines at all times. So that when you turn on the shower in the room that’s farthest from our water heaters, you don’t have to wait for all the cold water to pull through the lines to get to you.

Like say you’re the first client that gets out, we don’t want you to pull all that cold water towards you. We want it pretty much warm right away. But what they’ve done for these tankless water heaters as an option is they’re saying Well, “Let’s include a recirculation pump. So water is always cycling past that heat exchanger.” Well, my problem with that is that you’re losing this efficiency, right? Like, the idea was that you’re not, you know what I mean? Like you’re not using electricity when you’re not actually running the water. So I think that kind of shoot that in the foot.

On top of that, it’s hard on equipment, you know what I mean? Like, if it’s running continuously, like that’s tough on equipment. You’re going to see failure over time. And, again, Float Center, we see a lot of showers. We’re seeing a lot of tourists. This is not a residential application. So ours are working all the time. So like, I think those are kind of like at odds with each other. I guess a storage tank, I’ve seen a storage tank as well like a small storage tank but then like you’re cobbling things together. I guess what I’m saying is that they both have positives, they both have negatives.

Graham: Hey, the cold water sandwich is an interesting one. That’s one that didn’t pop to my mind when I was thinking about the on demand water heaters specifically.

Jake: Yeah. It really pops to your mind when they have an electric unit and you turn it on and then you’re sitting there for like 45 seconds and like starting to get goose bumps.

Graham: Okay. So, let’s say we were building Float On, again or another Float On.

Jake: Okay. Nice.

Graham: What would we aim for? Like would we try to get these on demand water heaters and make them work?

Jake: I would.

Graham: Okay.

Jake: Yes. I like the fact that they’re wall mounted. They take up less of a footprint. I like that it’s on demand heating. I might consider looking at the layout to my rooms. I don’t know if I would do just one tank per room. So, let’s talk about like their capacity there for a second. I know before I said it is rated on the temperature change from your source water and what flow rate you get. Well you have different levels of equipment out there. If you have an electric unit, you’re only really getting like 1.5, two gallons per minute, if you’re trying to change like 70 degrees 77 degrees or something like that. Whereas a gas unit that’s hot almost instantly, those are getting up to four or five, six. And then of course efficiency ratings and everything like that.

Graham: Which is actually a good point too, just to slide in a little pro tip there.

Jake: Nice.

Graham: Which is depending on what area, what kind of geographic area you’re in. How cold it is and what season it is.

Jake: Yeah.

Graham: You might actually need to look at different on demand water heaters.

Jake: Yeah, absolutely.

Graham: Because it’s the difference between that source water and what’s coming out, not just the difference between water.

Jake: For sure. Absolutely source water changes.

Graham: And what’s coming out. So, yeah if you have really cold winters-

Jake: Yeah.

Graham: You’re probably going to need a more hefty-

Jake: Well the ground keeps it pretty, like consistent, but it is definitely colder than if you’re in like a super warm climate. And what I thought you were going to jump to was like a location of like, a building.

Graham: The more intelligent thing I could say.

Jake: No, no, no, no, no, both amazing things. But the one that does jump is so like gas versus electric, if you want to put your float tank center and into like one of these new condo high rises and you want your retail space directly below it, you may not be able to have gas units because like, you need to be able to vent the gases from combustion. So like that is an interesting thing that we’ve seen people that want to have a gas line, but then they’re like, “You can’t exhaust that below someone’s window or something like that.” So yeah, definitely an interesting little thing there.

Graham: Yeah.

Jake: Cool.

Graham: Sorry to derail you.

Jake: No. No. No yeah.

Graham: Okay. So we would go with on demand. Would we try to solve the yeah. Okay.

Jake: Yeah, that’s right. Yeah. No. We would try to solve that problem. We would think about maybe coupling a few together. We’ve seen people branch a couple tankless water heaters. So like three units, all three of them branch in one single supply line kind of running all the time and stuff like that. If you have pretty good capacity and people are floating pretty regularly. And it seems to blend out as well. We’ve heard that it mitigates some of that. And then you can have a situation where you’re branching through together and running like a five tank center or something like that. So, other water demands, just real quick to get those in there, your washer and dryer or your washer or dryer doesn’t use any water.

Your washer, you have faucets right in the bathroom I guess I like three quarters of a gallon. And that’s really kind of it for like hot water. Your utility sink and keeping in mind that people are not showering in 110-120 degree water, like that’s just too hot. Especially before your floats we recommend a tepid shower.

Graham: Dishwasher I guess if-

Jake: Yeah, dishwasher for sure.

Graham: You’re hooking like a water cooler something directly into a supply line as opposed to

Jake: A lot of it yeah. If it’s indirectly in, a lot of those watercolors have heating known for-

Graham: I guess it’s there any in line water heater themselves oftentimes.

Jake: Is that where they got the idea for these float thanks? All right. Cool. I think that’s all I really have about water heaters. That answer the question?

Graham: Yeah. Yeah they were just wondering should they go with their instinct to go with tankless or should they be looking into other options.

Jake: I guess to make that succinct and quick, storage tank water heaters a little bit cheaper just make sure they’re well insulated, make sure you get really efficient ones. They do great. Sometimes when we start seeing large float centers, instead of getting a larger unit because that’s going to suffer from more latent heat loss and they’re less efficient. We’ll see people put a couple of them in series, basically daisy chained together. So hot water source going into one, pump it into another and then out to the float rooms. That’s actually what we have it Float On 2 67 first hour rated units daisy chained together.

And then tankless water heaters in an ideal world with bottomless pockets. Yeah, that’d be great. I’d love to have always hot water no matter what. Because you know what’s crazy, we’ve heard this a couple of times, actually. There are clients out there and again, we love our clients. These people are amazing, but there are clients out there that will take their showers. They’ll take a shower, and then they’ll leave the shower running and then they’ll float the whole time with the shower just running because they like the sound of the water or something like that.

Graham: We’ve had this happened at Float On specifically.

Jake: Yeah, we’ve heard of this at Float On. We’ve heard of it at least at three other float centers. At first we thought that was just a crazy one off but it’s happened multiple times. We’re like when your clients’ here, they might just like turn on the hot water and it doesn’t matter how much storage tank you have, like that’s going to all be gone unless you had on demand tankless water heaters. Yeah.

Graham: A rare case but still nonetheless, it is really frustrating like we have had a single client just mess up 12 showers essentially, like six people getting out of their float tanks couldn’t shower with hot water and then the next six people getting in didn’t have hot water just because this person really wanted I guess to have like a waterfall sound effect mid-float.

Jake: Yeah, the six exiting right after their float did not appreciate a really cold shower. Yeah.

Graham: Great. We love our clients though. Great clients.

Jake: We love them. We love them. They’re all amazing. Thank you so much.

Graham: All right. And if you have your own questions head on over to floattanksolutions.com/podcast.

Graham: And we will see you tomorrow. Talk to you tomorrow. Not actually see you.

Jake: Yeah, no. We might be I don’t know.

Graham: We’re not watching all of our listeners. That’d be weird.

Jake: You’re going to Portland be tomorrow? All right, we’ll talk to you tomorrow.

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